Species Profile: Pinfish, Lagodon rhomboides - SRAC Fact Sheets

HCG is approved for use as a spawning induction aid
in marine finfish. Recent research has shown that a single
dose of 500 to 4,000 IU/kg is effective for ovulation and
volitional spawning in pinfish. Using HCG, single spawns
of up to 50,000 eggs have been collected. Future research
will determine effective doses based on production goals.
Captive pinfish have only rarely produced natural
volitional spawns, and spawning cues are not fully understood.
Spawns have been collected at a salinity of 35 g/L
and temperatures of 68 to 77 °F (20 to 25 °C). However, it
is not known whether light cycle, aggregation size, tank
size, moon phase, or tide influence spawning in the wild.
Artificial fertilization, also known as strip spawning,
may be possible and can be accomplished by mixing the
mature ovulated eggs with freshly collected milt in seawater.
This may be useful, but further research is needed to
define missing spawning cues and to learn whether individual
fish will spawn multiple times per spawning season.
Eggs and larvae
Fertilized pinfish eggs (Fig. 2) have a single oil globule
and a spherical yolk and are buoyant in seawater. Eggs
range in diameter from 0.90 to 1.05 mm. Fertilized eggs can
be collected by skimming water from the surface of spawning
tanks and concentrating the eggs in screened collection
devices. Many different designs will work; the most common
design is to collect eggs in an external collection tank
equipped with a screen
(≤ 0.8-mm mesh diameter)
to concentrate the
eggs. Water leaving the
culture tank through
an open standpipe on
the surface of the water
will collect floating,
viable eggs. Sinking,
non-viable eggs can be
collected through a pipe
near the bottom of the
Figure 2. Pinfish late-stage embryos.
culture tank. The eggs
should be incubated in
static cylindrical tanks
filled with seawater from the broodstock system and gently
aerated with a submerged airstone. Eggs hatch after 24
hours of incubation at 77 °F (25 °C).
Endogenous nutrients in the larval yolk sac are crucial
for early post-hatch development (Fig. 3). Larvae are
extremely fragile during this early developmental period,
when eye pigmentation, swim bladder inflation, and jaw
formation occur. The yolk sac is absorbed at approximately
3 days post-hatch (DPH) at 77 °F (25 °C), and at
this time larvae must consume exogenous food to survive
Figure 3. Pinfish larva 2 DPH.
Figure 4. Pinfish larva 3 DPH.
(Fig. 4). Live zooplankton such as rotifers and/or copepods
should be introduced into the larval culture tanks at
this point. Although copepods are the natural food source
for wild larval pinfish, protocols for efficient feeding of
larvae need to be developed and cost effective live feeds
need to be identified.
Pinfish larvae should be cultured at approximately 77
°F (25 °C) and fed rotifers, Branchionus sp., at first feeding
(3 DPH) because they are small enough to be consumed.
Rotifers should be fed to larvae at a density of 5 to 15 rotifers
per mL from 3 to 21 DPH (Fig. 5). Rotifer cultures can
be fed live microalgae or algal paste and supplemented with
Super Selco® (INVE Aquaculture Inc., Salt Lake City, Utah,
USA) twice daily to enhance the nutritional composition.
Rotifers also must be enriched to attain adequate HUFA
concentrations to meet the nutritional requirements of
larvae. After enrichment, rotifers should be fed immediately
or stored in a refrigerator at 48 °F (9 °C) to slow the
digestion of the enrichment product.
Figure 5. Larval feeding regime.
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